Frame for air filters



Aug. 31, 1954 F. T. SENS 2,687,781

FRAME FOR AIR FILTERS I Filed Sept. 27, 1951 -mW////A um 32 33 Fred 7'. 56/75 IN V EN TOR.

ATTORNEYS Patented Aug. 31, 1954 FRAME FOR AIR FILTERS Fred T.Sens,-Newark, Ohio, .assignor to Owens- Corning Fiberglas Corporation, a corporation of Delaware Application September 27, 1951. Serial No. 248,531

3 Claims.

Thisinvention relates to frames for air filters of the type in which a mat, of heterogeneously arranged somewhat loose fibers is mounted in a frame. work and retained in. generallyrectilim early shape, the filter as a whole beingplaced in a stream of air for example in an airconditioning or heating plant,,for the purpose of filtering dust and other foreign objects out of the air.

.In my copending application Serial No. 244,120, filed August 29, 1951,, there is disclosed and claimed a frame for an air filter of thistype in whichthe structural elements of the frame consist in perforated face plates extending across the major faces of the mass of fibers and thin tough sheet material, preferably lightweight cardboardarranged to secure support andspace thetwo thinperforated facelplates from each other.

:It is an objectof the present inventionto provide a lightweight sturdy sideframe element for such an air filter. .which constitutes a sim .plification and improvement over the frames disclosed in my copendingpappl-ication and over frames such as areemployed in theart in general.

It is another object of this invention to provide a frame construction for an air filter in which no mechanical attaching means is required to secure the metal grills or perforated face plates to the side frames and thus in which weight and cost of assembly are both considerably reduced over conventional prior art structures.

It is yet another object of this invention to provide a lightweight filter frame in which the side frame members, i. e., those members which space the face plates from each other are fabricated from lightweight but structurally strong corrugated elements and in which such corrugated elements are adhered the edges of the metal grills.

These particular objects will be better understood from the specification that follows and from the drawings in which:

Fig. 1 is a perspective view of an air filter incorporating a frame embodying the invention.

Fig. 2 is an enlarged fragmentary vertical sectional view taken substantially on the line 22 of Fig. 1. i t

Fig. 3 is a fragmentary view partly in plan and partly in section taken along the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2 but of a modification of a side fram incorporating the invention.

Til

. An air filter of the. type which ,a frame. embodying the invention. isfldesigned, toenclose and mount consistsin agencrally rectilinear mass of heterogeneously. arranged fibers .10.. The

fibers It serve to catch dust, pollen and other particles and to filter the same out of the stream of air passing throughthe mass of fibers. .The fibers. ltimay beproduced from rockwool, glass OrsimiIar synthetic .or natural materials... which can be drawn or blown orotherwisearranged in loosely compacted masses. of [.fibersand formed in the propershapes.

The. filter consisting. in, the. mass of. fibers I 0 haspractically no. mechanical strength and thus it is mounted, betweennperforated. face. plates H and 12 which, in the typeyof filter. shown inlthe drawings,,may comprise thin. sheet metal plates or grills so designed as. to. .holdthe, fibersin a mass, but to. allowthe passage .of asubstantial- 1y unrestricted flow .of air through the fibers.

,A frame for afilter. cmbodyingthe invention may consisting f01d..of..th in fibrous material such as lightweight cardboard l3 which is folded over the. edgeof. the-uppergrill. Hand S cured in. place i thereon by a mass of adhesive.

i 4fi1lingapertul'es, l5 in-the grill'll ,along the edge of the grill II and adhering the strip of material It to the edge of the grill It and to itself. The grill ll may be so cut as to provide for a thin web of material l6 that is buried in the fold of sheet material [3 with the adhesive M serving to prevent the sheet material [3 from separating from the grill l I.

A similar fold of sheet material I! similarly is adhered along the edge of the lower grill l2.

Extending transversely to the planes of the grills or face plates II and I2 and adhered to the inner sides of the folded strips of sheet material l3 and I l is a filter side wall [8 which consists in a relatively heavy, narrow strip of corrugated cardboard or similar material having an inner facing sheet I9, an outer facing sheet 20 and a corrugated bracing element 2i. A coating of adhesive 22 adheres the edges of the wall I8 to inner folds 23 and 24 of the strips of sheet material l3 and I7.

The folds of the strip material l3 and I! may be overlapped at the corners of the filter structure as indicated by the reference numeral 25 in Fig. 1 to further strengthen the frame as a unit.

ment 2|, the strength of the perimetrical walls of sheet material 30 that is the unit as a whole is considerable. The filter frame may be assembled by first adhering the inner folds 23 and 24 of the strips l3 and H to opposite edges of the wall 18; then placing sheet metal grills or face plates H and I2 on the outside surfaces of the folds 23 and 24; and then folding the strips of sheet material l3 and I! around the edges of the grills II and I2 respectively, with sufiicient pressure to adhere the assembled elements to each other, the wall l8 serving satisfactorily to resist the pressure necessary to cause such adhesion.

In Fig. 4 there is illustrated a modified form of frame embodying the invention in which a side wall 26 consisting of a corrugated bracing element 21 and inner and outer sheet elements 28 and 29 is enfolded in a wide strip of thinner adhered to the outside of the element 29 and extends outwardly beyond and is folded over and adhered to the upper and lower face plates or grills 3| and 32 respectively. A mass of adhesives 33 extends through apertures 34 in the grills 3| and 32 in a manner similar to that in which the adhesive I4 is used in the embodiment of the invention illustrated in Fig. 2.

The strip 30,. being folded over the outside edges of the grills 3| and 32, both serves as a base for the adhesive 33 and as a decorative cover for the edge of the assembled grill structure.

The generally flat perforated face plates or grills H and I2 or 3! and 32 as the case might be, thus are retained in parallel shaped relationship for the retention and support of the generally loose mass of. fibers H]. The cross walls l8 or 26 respectively, strengthened by the corrugated elements 2| and 21 respectively, function both to space the face plates or grills from each other and to form the side protective walls for the frame for the mass of fibers 10. The transverse strength of the walls 18 and 25, resulting from the corrugated elements therein, provides ample structural strength for the side frames without addingsubstantial weight to the complete filters and provides for securing the elements of the filter frame to each other with- 4 out mechanical securing means such as staples, wires or clips.

A filter frame constructed according to the invention thus is light in weight, low in cost of materials required and simple to assemble.

I claim:

1. An air filter comprising a generally rectilinear mass of fibers, a frame encompassing said mass and comprising a pair of spaced parallel grilles located on opposite main faces of said mass of fibers, a transversely extending side Wall located between the inner faces of said grilles about the edges thereof to space the grilles apart, and a U-shaped channel of sheet material extending along each of the four sides of said filter and received over and enclosing said side wall and the edges of both of said grilles, the flanges of said U-shaped channel being adhered to said grilles and the web of said channel being adhered to said side wall.

2. The air filter of claim 1 wherein the side wall is a corrugated element having fiutings extending perpendicularly to said grilles.

3. A filter according to claim 2 in which said channel of sheet material extends only over the outer side of each of the edges of said grilles and the edges of said cross wall contact the inner sides of said grilles, and a layer of adhesive extending through perforations in said grilles between the edges of said cross wall and the said channel of sheet material.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,008,751 Davies July 23, 1935 2,138,874 Myers Dec. 6, 1938 2,232,065 Hasselwander Feb. 18, 1941 2,459,802 Fleisher Jam-25, 1949 2,569,575 Phillips Oct. 2, 1951 FOREIGN PATENTS Number Country Date 482,543 Great Britain Mar. 31, 1938 

